package singleton;

import java.sql.SQLOutput;

/**
 * 饿汉式
 * 类加载到内存后,就实例化一个单例,JVM保证线程安全
 * 唯一缺点:不管用到与否,类加载时就完成实例化
 */
public class Mgr01 {

    private static final Mgr01 INSTANCE = new Mgr01();

    private Mgr01() {};

    public static Mgr01 getInstance() {return INSTANCE;}

    public void m() {
        System.out.println("m");
    }

    public static void main(String[] args) {
        Mgr01 m1 = Mgr01.getInstance();
        Mgr01 m2 = Mgr01.getInstance();
        System.out.println(m1 == m2);
    }

}
